1. LG 47LN540V LED TV was repaired with the defect “no picture, there is sound” 2. Samsung UE40H6233AK LED TV was repaired with the “dim image” defect 3. LG 32LN541U-ZB.BDRMLDU LED TV was repaired with the “no” defect Images". Upon opening, one burnt-out diode was discovered. 4. LED TV Samsung UE32F5000AK was repaired with the defect “no picture, there is sound” 5. LED TV LG 42LA615V-ZE (42LA620V) was repaired with the defect “no picture, there is sound” 6. LED TV Bravis LED32C2000B, LED- 32C2000B, as usual, no image, no backlight. 7. LED TV Supra STV-LC40T400FL no image, no backlight. 2 LEDs burned out
8. LED TV LG 50LB653V-ZK was repaired with the defect “flickers, blinks, picture, sound is present” 9. LED TV LG 55LB631V backlight - no picture, there is sound.
10. LED TV LG 39LA620V backlight - no picture, but there is sound.
11. LED TV LG 32LH604V - the backlight is not working properly, the color rendering is poor, there is a lot of blue color, there is sound.
12. LED TV LG 37LN541U - the backlight is faulty, there is no image, there is sound.
13. LED TV Samsung UE40D6100WX was repaired with the defect “does not turn on, the standby indicator is blinking”
14. LED TV 32LED38T2P - the image is barely visible, there is sound.
15. LED TV LG 43LV761H - the backlight is not working properly, the color rendering is poor, there is a lot of blue color, there is sound.
16. The Samsung UE46EH5000W LED TV was repaired with a “no image” defect and the backlight does not work.
17. LED TV BBK 55LEX-5027/FT2C was repaired with the defect “no image”, the backlight does not work.
18. LED TV Samsung UE43J5202AU was repaired with a “no image” defect, made in China, the backlight does not work.
19. LED TV LG 32LJ510U - the backlight is not working properly, the color rendering is broken, the image is blue, there is sound.
So, let's begin.
1.LED TV LG 47LN540V was repaired with the defect “no picture, there is sound”
- Direct LED lighting
- LEDs for 3V, 1W, 27.03004 from LG was used for replacement
- Number of LEDs - 54 pcs.
- Lenses - small, droplets
- Substrate - fiberglass
- Number of backlight driver channels - 1
LEDs for LED backlighting of TVs. Where to buy and reasons for failure.
Hi all. In this article I will talk about LED backlighting of TV matrix , namely why the LEDs in the backlight burn out, where you can buy them, and how to prevent them from failing again.
About LED backlighting of the TV matrix.
The first LCD TVs were backlit using fluorescent (CCFL) lamps. This type of backlight worked very well, but the brightness of the glow left much to be desired. Such TVs were inferior in image quality to plasma panels, but were superior in size and weight.
Since science does not stand still, instead of CCFL lamps they began to use LEDs, which, with their bright glow and low current consumption, gave a milestone in the development of LCD TVs. Of course, the matrices themselves also improved greatly in quality and color reproduction during this time, so the dim glow of CCFL lamps could not fully convey the picture that manufacturers would like to see.
Reasons for failure of LED TV backlights.
Since I often repair TVs, and on my old website I described the repair process more than once, for myself I can identify several main reasons for the failure of LED LEDs.
The first reason is a shortcoming of the manufacturers themselves. Very often, based on my experience, the manufacturers themselves configure the backlight driver in such a way that the LED lines receive more current than they should, as a result of which the LEDs overheat and fail.
The second reason is the defective LEDs themselves. It happens that after disassembling the matrix you find only one faulty diode. At the same time, the current that goes to the matrix is within normal limits, and all other LEDs are in excellent condition.
The third reason is directly related to the first. Some owners like to watch TV at maximum brightness (the backlight is on 100%). Since the manufacturers of some TVs specifically increase the current supplied to the LEDs, viewing in this mode does not in any way add to the life of the TV backlight. I recommend not increasing the backlight level above 70%. In this mode, your TV will work much longer.
What LEDs do I use to repair LED TV backlights and where do I buy them?
I buy all LEDs on Aliexpress from trusted sellers. I will show you how to search for and replace LEDs on strips in subsequent articles, but now I will post a list of the most popular LEDs that are used in backlight repairs.
| Photo | Name | Purchase link |
| LEDs 2 W 6 volts on LG size 3535 (large anode pad (+)) | Buy here | |
| LEDs 6 volts on LG 1 W size 7030 | Buy here | |
| LEDs 3 volts on LG 0.5 W size 7020 | Buy here | |
| LEDs 3 volts on LG size 3528 (large anode pad (+)) | Buy here | |
| LEDs 3 volts on Samsung 1 W size 3537 | Buy here | |
| 3 volt LEDs for Samsung size 7032 | Buy here | |
| LEDs 3 volts on Samsung 0.5 W size 5630 | Buy here | |
| LEDs 3535 2 watts 6 volts on LG (large platform cathode (-)) | Buy here |
I buy other less popular LEDs here.
To glue the lenses after resoldering the LEDs, I use E8000 . I use it to glue the sensors of tablets and phones. I buy glue here:
Adhesive for lenses and touchscreens.
When purchasing on Chinese sites, do not forget to use cashback. What cashback I use is described in this article .
The best TV repair course, thanks to which I learned how to repair TVs, is here.
In future articles I will describe the entire process of replacing LEDs on LED backlight strips. Thank you all for your attention and good luck with repairs and homemade projects.
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LED TV Samsung UE40H6233AK received a repair with a “dim image” defect
- Direct LED lighting
- LEDs for 3V, 1W - 27.03010
- Number of LEDs - 39 pcs.
- Lenses - small, droplets
- Substrate - aluminum
- Number of backlight driver channels - 3
How Ambilight and its analogues work
First you need to understand how it all works. A special module captures and analyzes the image on the screen to understand the color of the area around the perimeter of the matrix. After this, a similar signal is sent to the addressable RGB strip located behind.
Capture is performed several times per second, and the glow of the diode strip behind is updated at the same frequency. Of course, this requires serious resources. The higher the image resolution, the more pixels have to be processed during capture.
All solutions that replicate Ambilight technology are divided into two types: based on an external decoder or based on a set-top box .
◉ The first type is a separate box with an HDMI input and a similar output. Inside is a small single board computer (most often based on a Raspberry Pi) that accepts the output signal from any source. TV set-top boxes or consoles can be connected to the input. The capture process takes place inside, and the output image is displayed on the TV.
The advantage of this solution is ease of connection. No complex circuits, additional software or settings. The box is simply placed between the signal source and its receiver (TV).
The disadvantage of such a box is also obvious - most often it will produce a picture worse than at the input. The power of the module may not be enough to rebroadcast 4K, sometimes there will be no support for HDR, there are cases when the boxes do not support the required FPS or simply do not transmit surround sound. Here everything depends either on the power of the filling or on the standard of the HDMI port.
